high energy particle detection through prototype gas electron multiplier systems j.slanker, d....
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High Energy Particle Detection through prototype Gas Electron
Multiplier Systems
J.Slanker, D. Dickey, K. Dehmelt, M. Hohlmann,
L. Caraway
Florida Institute of Technology
Department of Physics and Space Sciences
March 18, 2005
What Is a Gas Electron Multiplier (GEM)?
L. Caraway
Applications: -particle tracking at accelerators -X-ray imaging for space-based high-energy astrophysics -applications/designs for Homeland Security -aging of substances-medical imaging
The GEM
• Our purpose to serve as a detector for high energy ionizing particles (usually gamma rays), and to image the substances that emit the radiation.
How It Works- Incident ionizing particle -ArC02 (70% Ar, 30% CO2) mixture -Photoelectric Effect and Compton Scattering -relectons are accelerated towards the induction plane -large electric potentials created by the GEM foils around 300V to 500V. -“cascade”
-gain
F.Sauli
Example of a triple GEM.
F.Sauli
Close-up of GEM foil
SystemA) Voltage Source for HV boardB) HV board provides voltage for GEM foils.C) Radioactive Source provides impetus for
cascade.D) Output signal amplified by linear
amplifier.E) Signal interpreted by oscilloscope or
Labview programs.
Results of Experimentation
• Results for experimentation proved inconclusive.
• Signal seen from triple GEM may have incorporated the desired signal.
Results seen from Single GEM detector
Problems To OvercomeProblems with the triple GEM:
-Sparking inside GEM, most likely due to humidity.-Keeping out out-gassing substances/substances which interfere withoperationas well as unwanted electromagnetic interference.-Keeping GEM foils clean.
SubsequentThe 10x10 GEM
Plans are currently being madefor the next generation of GEMusing a “10x10 triple GEM” to accomplish what we set out to do in the first two GEM detectors.
F. Sauli
Acknowledgements
http://chall.ifj.edu.pl/~lesiak/detectors_yr02.pdf
Good sources for GEM information:
http://www-hep.uta.edu/hep_notes/lc/lc_0001.pdf
http://www-flc.desy.de/thesis/diplom.2004.voigt.pdf
Special Thanks to:Georgia Karagiorgi
Outgassing Information:http://outgassing.nasa.gov/
GEM Graphics: (in order of appearance)
L. CarawayF. SauliK. Dehmelthttp://gdd.web.cern.ch/ GDD/using.htm